Research On Preparation And Properties Of Polymer-based Insulation Friction Materials Of Ultrasonic Motors

The ultrasonic motor is a kind of actuator that can realize driving function through mechanical vibration under the ultrasonic frequency domain.It has the advantage of fast response speed,low speed but big torque,and good starting and stopping control,etc.The ultrasonic motor is widely used in aviation,aerospace,military and other fields.Ultrasonic motor friction material is the key part of ultrasonic motor,and it is directly related to the driving performance and service life.In order to adapt to the use of the environment,new requirements for the insulation of ultrasonic motor friction materials are put forward.Therefore,it is very important to develop a kind of friction material with good insulation,mechanical properties,tribological properties and excellent ultrasonic motor performance.First of all,through new requirements for ultrasonic motor generated by integrated high frequency and high voltage environment,the selection of packing materials and the preparation process of friction materials are studied.In order to analyze the insulation mechanism of ultrasonic motor friction material,a conductive model of polymer matrix friction materials of ultrasonic motor is established.The model described the conduction modes of charges in polymer matrix composites,and compares the components of fillers with electrical devices.The model studied the charge law of volume resistivity with the content of conductive particles to lay a foundation of obtaining excellent ultrasonic motor insulation friction material.In order to obtain good insulation properties,good wear resistance,and meet the high load performance requirements of ultrasonic motor friction materials.The influence of different content of polymer A,aluminium oxide A,molybdenum disulfide and polytetrafluoroethylene on the mechanical properties,tribological properties and electrical properties of the friction materials was studied by single factor method.The influence mechanism of each filler was analyzed from various aspects,and the reasonable dosage range of filler was obtained.In this paper,the method was put forward with polytetrafluoroethylene as matrix,polymer A as reinforcing filler,the use of molybdenum disulfide and aluminum oxide A substrate for modification.Using compound formula orthogonal design experiment,the ultrasonic motor performance with each formula component was studied,and the adjustability for formula component to the formula performance was realized.The optimum formula is optimized by means of variance analysis and validate,and a kind of insulation friction material of ultrasonic motor with excellent comprehensive performance is developed.By comparing with the commonly used friction materials in China and the real machine experiments,The results show that the material has good mechanical properties,good wear resistance,meets the insulation requirements,and has good driving performance.It provides a theoretical and experimental basis for the application of material in ultrasonic motor.